Technical Field
The present disclosure relates to an image capturing optical system and an image capturing device, and more particularly, to an image capturing optical system and an image capturing device applicable to electronic devices.
Description of Related Art
As personal electronic products nowadays has been becoming more and more compact, the internal components of the electronic products are also required to be smaller in size than before. Except for the demand of miniaturization, the advanced semiconductor manufacturing technologies reducing the pixel size of sensors have also pushed compact optical systems to evolve toward the field of higher megapixels. In addition, the popularity of smart phones and tablet personal computers also significantly increases the requirements for high resolution and image quality of present compact optical systems. Therefore, there is also an increasing demand for compact optical systems featuring better image quality.
In a conventional five-element optical system, the fourth lens element generally has a convex image-side surface. However, under this configuration, the convex image-side surface of the fourth lens element has a larger curvature and the variation of the thickness of the lens is more pronounced, thus shortcomings, such as formation difficulties of lenses and excessive optical sensitivity may occur easily. Moreover, the refractive power of the second lens element in the conventional five-element optical system is usually poorly distributed and unable to effectively balance the positive refractive power of the first lens element, thus the light will bend drastically and the aberration cannot be eliminated easily.
Therefore, a need exists in the art for an optical system that features compact size, better image quality, and an appropriate sensitivity of the system.